Shallow well pump losing water pressure with garden hose attached

We have a 1 1/4 hp shallow well jet pump, it is wired to a switch that we turn on and off, there is no storage tank. We use it strickly water water outside. Anyway, we just replaced this pump with a new pump, we primed and it ran fine for 3-4 days, now we are losing water pressure when we connect a hose, any garden hose, but the pump is pumping a continous flow when no hose connected, but the pressure seems to be low. Any suggestions as to what could be wrong.

Things we have done, cleaned the ejector, found nothing blocking, changed water hoses. Left water hose off and pump runs, but pressure not as strong as should be, also found some air in hose.